Immunisation in immunosuppressed dermatology patients

Background: Immunodeficiency

Immunodeficiency can be caused by inherited syndromes, infections, drugs, medical conditions, pregnancy, ageing and many other factors. Immunodeficiency is defined as inadequate functioning of the immune system. It can occur at multiple points across the immune response. It can then lead to:

Lower doses or shorter courses of systemic steroids are not considered significantly immunosuppressive. Low-dose methotrexate used for skin diseases mainly acts as an anti-inflammatory drug and is only weakly immunosuppressive.

Immunisation prior to immunosuppression in dermatology patients

In dermatology we are frequently responsible for patients commencing immunosuppressive treatment for inflammatory skin disorders. Whenever possible, immunosuppressive treatments should be delayed until immune status has been optimised.

Step 1: Take an immunisation history

Prior to starting immunosuppressive therapy, determine the following:

Prior vaccinations. Each country has its own recommendations for vaccination with different vaccines given at different ages.

From time to time additional vaccines are included, e.g. prevalent meningococcus strains.

Changes to the schedule for 1 July 2014 add rotavirus vaccine, varicella vaccine (for high-risk immunosuppressed patients), hepatitis A vaccine (for eligible patients) and a monovalent meningococcal C vaccine. The HPV vaccine is changed to 'up to 18 years'. Revaccination of children following significant immunosuppression will also be funded. The pneumococcal vaccine will be replaced by a 13-valent product and the current polysaccharide meningococcal A, C, Y and W-145 vaccine will be replaced by a conjugate product.

Other non-funded vaccines are available against varicella, various meningococcus strains, tuberculosis (BCG), rotavirus and seasonal influenza. Vaccines recommended for travel may include hepatitis A, cholera and yellow fever.

Live injected vaccines are MMR, oral polio (not IPV), varicella, zoster (shingles), yellow fever and BCG. There are live oral vaccines for rotavrus and typhoid. These are best avoided while on immunosuppressive medication because they may result in severe vaccine reactions.

Step 2: Perform appropriate tests

If starting a cytotoxic drug such as cyclophosphamide or biologic therapy, or if considered at high-risk of TB from the history, screen for tuberculosis. Methods include:

QuantiFERON gold blood test

Mantoux skin test

Chest X-ray.

Check varicella, measles, hepatitis A/B/C and HIVserology. (There are no vaccines for hepatitis C or HIV).

Step 3: Vaccinate prior to starting immunosuppressive therapies

To avoid the risks of preventable infections:

Give any outstanding vaccinations from the childhood schedule*. Note, the second MMR can be given as early as 1 month after the first.

Immunise if not immune, even if previously vaccinated to the specific infection, including chickenpox/varicella-zoster vaccine.

Recommend pneumococcal vaccine and annual influenza vaccine. In New Zealand, subsidy for pneumococcus and influenza vaccine is available for immunosuppressed patients under some circumstances.

Step 4: Vaccinations after starting immunosuppression

Continue routine non-live vaccination schedule.

Have seasonal influenza vaccine each autumn and consider a boost if immunosuppression is severe.

Avoid live vaccination of patient and siblings once immunosuppressed (live polio, chickenpox/varicella, herpes zoster, yellow fever). MMR, BCG are exceptions and can still be given to immunosuppressed patients and their household contacts.

All patients on immunosuppressants should be warned that they are at risk of more severe infections than usual. They should be told to alert their care team if they are exposed to chickenpox (varicella) or measles.

Exposure of immunosuppressed patients to varicella and measles

Patients who are significantly immunosuppressed and are exposed to varicella or measles need to be given passive antibody protection, whether or not they have detectable antiviral IgG antibodies.

Passive antibody protection is not considered necessary for those who have evidence of immunity with detectable IgG antibodies and are taking methotrexate as their only immunosuppressive drug.

Varicella

There is a significant risk of varicella if a non-immune person is exposed to the virus during the infectious period. This occurs from 2 days before the rash appears until the blisters have crusted over. The incubation period after exposure is 7-21 days. ‘Significant’ exposure is considered to be 15 minutes of close contact/play with a contagious individual.

If an immune suppressed patient is in contact with varicella, passive protection should be provided with varicella zoster immune globulin (VZIG) within 96 hours (ideally 72 hours) of contact.

Measles

There is a significant risk of measles if a non-immune person is exposed to the virus during the infectious period. This occurs from 5 days before the rash appears until 4 days after the onset of rash. The inclubation period for measles is 10-14 days after exposure. ‘Significant’ exposure is considered to be 15 minutes of close contact/play with a contagious individual. Measles in the contact should be confirmed by viral serology, as measles rash may appear similar to other viral exanthems or morbilliform drug eruptions.

If an immune suppressed patient is in contact with measles, the following treatment is recommended regardless of antibody status.